Abstract
A mixed culture experiment in which each of two sorghum varieties was associated with two soybean varieties respectively was conducted in Fukuoka, Japan, to evaluate the effects on the dry matter production, efficiency of light energy utilization and other growth factors. 1) Though the dry matter yields in the mixed cultures did not over-yield the sorghum pure cultures, the relative yield total in all the mixed cultures was over 1.0. The efficiency of light energy utilization in all the mixed cultures was higher than the each pure culture especially at the later growth stage. The different combination in mixed cultures had little effects on the dry matter yield and efficiency of light energy utilization. 2) The CGR of sorghum in the mixed cultures were higher as compared with the sorghum pure cultures in the later growth stage, which was brought about by the high NAR of sorghum in the mixed cultures. The higher NAR in the mixed cultures was explained by the increase in the estimated net photosynthesis per unit leaf area and lower SLA of sorghum in the mixed cultures. 3) In the mixed culture of sorghum and soybean, no paticular change in the competitive relationship between both species was recognized in any of the different combinations.
